In the processing of fabrics, including but not limited to tubular knitted fabrics, finished or substantially finished fabric typically is gathered by rolling or folding. An advantageous form of fabric folding equipment, known in the past, is reflected in the Eugene Cohn U.S. Pat. No. 2,761,678, assigned to Samcoe Holding Corporation. In the apparatus of that patent, finished fabric is directed upward from the finishing equipment and is passed over a driven infeed roller. The fabric then is directed generally downward, between a pair of downfeed rollers, which are constantly reciprocated back and forth over a receiving platform. As the fabric is guided repetitively back and forth, it gathers on the platform in folded layers of relatively uniform length.
In the course of development of the fabric finishing art, constant improvements have been made in the linear speed at which it is possible to perform processing operations, to the point where processing of tubular knitted fabric, for example, may now be carried out at speeds in excess of one hundred fifty yards per minute. Heretofore, however, where the mill procedure has dictated gathering of the finished fabric by folding, the folding operation itself has served to limit the processing speed, because of the practical difficulties involved in folding a wide web of fabric at such high speeds. As can be readily appreciated, when attempting to reciprocate a web of fabric back and forth at high speed, there can be substantial resistance from the air to lateral movement of the web (sailing effect). In accordance with the present invention, a novel and improved horizontal folder arrangement is provided which minimizes and controls to an optimum extent sailing of the fabric during high speed folding movements. Additionally, when folding at high speed, constant, uniform downfeeding of the fabric is important, as any variations therein can substantially affect the uniformity of the folding operation.
In accordance with one of the significant aspects of the invention, a novel and improved arrangement is provided for constantly driving the downfeed rollers of a horizontal folding apparatus, to achieve substantially uniform downfeeding of the fabric, yet which is wholly consistent with high speed horizontal reciprocation of the rolls. To this end, a first drive arrangement is provided for reciprocating the downfeed rollers horizontally back and forth over the receiving platform, and an independent drive arrangement is provided for rotating the downfeed rollers, in order to maintain the rollers in continuous rotation, even at the ends of the reciprocating motion of the roll carriage.
Pursuant to another feature of the invention, in order to minimize reciprocating weight of the carriage and support mechanisms for the downfeed rollers, the independent drive means for the downfeed rollers is arranged for stationary mounting, and engages and drives the downfeed rollers through an endless belt or the like, which extends alongside the reciprocating path of the roll carriage. In conjunction therewith, novel arrangements are provided for effectively compensating for the fact that, during a portion of its cycle, the roll carriage is moving with the endless belt and, during the other portion of its cycle, the roll carriage is moving opposite to the belt. The arrangement of the invention takes advantage of the windage and inertia of downwardly feeding fabric is to cause the fabric to be driven by one roller, when the carriage is moving in one direction, and by the other roller when the carriage is moving in the opposite direction. Accordingly, arrangements are made for the respective rollers to be driven at different speeds relative to each other, to the end that the fabric feed is substantially constant speed in both directions of reciprocating travel of the roll carriage.
In order to accommodate adequately high speed reciprocating movement of the downfeed roller carriage, the apparatus of the invention includes a simplified and advantageous arrangement of counterweights, which move oppositely to the downfeed roller carriage, in order to achieve a balance of acceleration and deceleration forces at the ends of the reciprocating strokes.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment and to the accompanying drawings.